Topic: Could anyone explaine carburetors to me? v

[aquadorhj]

hi guys.

i was thinking about old cars yesterday.   i worked at my father's garage for almost a year, and during that whole time, i saw probably less than 10 cars that were carb'ed and never really did anything with carbs.

so i don't know how they work, and i don't know what it means when it has "triple deuce" or "double barrel" or whatever they say when they talk about old cars.

i did a brief search on triple deuce and that turned up nothing valuable in the first page.

so i turn to you guys.  what are the different variations of carburetors and how do they work?

[footlong58]

Man, you could read an entire book on this, its a science in itself.

Basically, its a device that atomizes/mixes your fuel with incoming air.  The more your step on the gas, the more the carb opens and sucks in more air and fuel.

The barrel term refers to the carburetor opening.  A standard carb is 2 barrel.  A 4 barrel has 2 more openings, which gets you essentially more power as it lets in more air.

Inside the carb you have needles and jets that are set to meter gas and whatnot.

[tpl]

Bernoulli's principle is the science behind carburetors.

So wiki comes to the rescue.  Wiki  Bernoulli   then venturi effect and then carburetor and you will know everything about carburetion.

After all that there are undoubtedly pages on all the ancillary stuff for emissions, cold starts etc etc.

[erich]

I did a presentation on carburettors in high school, too bad I don't have it any more. I could make you a sketch, though - PM me if you want
Carburettors are still used on motorcycles and small engines, you can take a lawn mower apart and see what's inside. Wikipedia has a good article too.

[No H2O]

I saw probably less than 10 cars that were carb'ed and never really did anything with carbs.

Too bad, because at least you can do something with carbs...like fix them roadside if needed. When fuel infection breaks down, you can't do anything but call a flat bed and replace parts.

[rrocket]

I'm skilled with carburetors as it pertains to jetting them....snowmobiles and motorcycles.  I have my laser temp gun and my magnifying glass. With those 2 tools, I can getting the jetting pretty darn close to perfect.... That being said, even with my skill, I prefer fuel injection tuning. All I need is a laptop for that!

 But trying to explain them in general to someone might take awhile.  Best to pick up a book.

[blur911]

Back in the '50s and '60s when American V-8 engines ruled the need for more carburetion came about there were no large carburetors on the market.  The immediate fix was to install more small carbs, hence the triple-two-barrel setups.  Then larger "four-barrel" carbs were developed to replace the multi-carb setups for both economic and tuning reasons (it's harder to setup multiple carbs)
The "barrels" are the number of venturis, big ones opening at lower flow rates don't work very well so many "four-barrel" carbs only opened two smaller barrels until approaching wide open throttle then the bigger ones opened as you have to have enough air velocity in the venturi to atomize the fuel properly.  
That's why simply putting a large carb on a small engine doesn't work, it might give you better power at high RPM and WOT, but at low speeds and part throttle it would work like crap.